胸腰椎压缩骨折中后方韧带复合体损伤与CT骨性影像学参数及生物力学的相关性分析

Correlation analysis between posterior ligamentous complex injury and CT bone imaging parameters and biomechanics in thoracolumbar vertebral compression fractures

目的:探讨CT骨性影像学参数[椎体楔变角(SIEA)、局部后凸角(LK)、棘突间距增加值(IISD)]在后方韧带复合体(PLC)损伤诊断中的可靠性,并从生物力学角度探讨压缩骨折后PLC的损伤机制。方法:选择胸腰椎(T11~L2)骨折外伤患者68例,测量CT骨性参数,并按MRI对PLC损伤状态的判断,分为损伤组36例和无损伤组32例,先将各项骨性参数行t检验,有意义的参数纳入二元Logistic回归分析,并根据ROC曲线分析参数预测PLC损伤的诊断效能。35例行生物力学分析,并对不同程度骨折患者给予垂直及前屈工况,判断不同工况与棘突间位移值改变的相关性。结果:2组CT骨性参数差异均有统计学意义(均P<0.05)。Logistic回归分析,表明SIEA与PLC损伤无相关性(P>0.05),LK、IISD与PLC损伤均有相关性(均P<0.05)。LK的ROC曲线下面积为0.760,IISD为0.834。生物力学t检验结果示:不同工况在Ⅰ度、Ⅱ度骨折患者的棘突间位移值改变中差异有统计学意义,且垂直力显著性大(P<0.05)。结论:在骨性参数中,LK及IISD是诊断PLC最有效的预测参数。垂直力对胸腰椎压缩骨折患者的棘突间位移值改变起主要作用。

Objective : To investigate the reliability of CT bone imaging parameters in the diagnosis of posterior ligament complex(PLC) injury,and to explore the damage mechanism of compression fracture from biomechanical perspective. Methods:68 cases of thoracolumbar fractures were analyzed. The parameters of superior inferior end plate angle(SIEA),local kyphotic deformity(LK) and increased interspinous distance(IISD) were measured. The t-test was performed on each bone parameter,the meaningful parameters were included in the binary Logistic regression analysis,and the ROC curve analysis parameters were used to predict the diagnostic efficiency of PLC injury. The biomechanical analysis was performed on 35 patients to compress the fracture. The degree was classified,and the vertical and flexion conditions were applied to patients with various fractures to determine the correlation between the displacement values of the spinous processes under different working conditions. Results:SIEA,LK and IISD were statistically significant between the PLC injury group and the non-injury group(P <0.05). Logistic regression analysis showed that there was no significant correlation between SIEA and PLC injury(P> 0.05),and LK and IISD were correlated with PLC injury(both P<0.05). ROC curve results showed that the area under the LK curve was 0.760,and the IISD was 0.834. The biomechanical results showed that there were significant differences in the changes of interspinous displacement between patients with type Ⅰ,type Ⅱ in different working conditions,and the vertical force was significantly significant(P <0.05). Conclusions:LK and IISD are the most effective predictive parameters. The vertical force plays a major role in different injury states and different fracture types.